Conventional pick up trucks generally have a truck box on a rearward end for carrying cargo. The use of a tonneau cover which is secured to the truck box is common for enclosing the truck box and for preventing theft of the cargo while the vehicle is unattended.
In U.S. Pat. No. 5,110,021 (Dawson) issued May 5, 1992 is disclosed a tonneau cover which includes two separate panels each of which is hinged to a respective side wall of the truck box. Each panel can pivot from a raised position in which it stands generally upwardly from the side wall to a closed position in which it lies generally horizontally across the truck box so that the two panels in the middle and close the open top of the truck box. A pair of rails are provided each mounted on a respective one of the panels and each extending from that panel to the other panel. The rails are spaced so that one is toward the front and one is toward the rear to hold the panels in the raised position and to act as a support for a load over the truck box. This arrangement has achieved no commercial success and the construction shown in the patent is of a simple and schematic nature with little attention to the important details of the mounting of the construction on the truck. box.
U.S. Pat. No. 6,224,140 (Hoplock) issued May 1, 2001 discloses a further device of the same general type which gives further details concerning constructions of the device and how it is attached to the side walls of the truck box. Again however this device has achieved no commercial success requiring a significant redesign of the construction.
In U.S. Pat. No. 6,340,915 (Hall) issued Jan. 22, 2002 is disclosed an arrangement of this general type and in particular shows a locking arrangement for locking the edge of one panel to the next adjacent panel to hold the panels in closed position.
In U.S. Pat. No. 6,254,169 (Arthur) issued Jul. 3, 2001 is disclosed a hinging arrangement for attachment of the panels to the top wall of the truck box.
In U.S. Pat. No. 6,598,930 (Tilton) issued Jul. 29, 2003 is disclosed a further arrangement of this type which includes a locking arrangement for locking the edge of one panel relative to the other.
In U.S. Pat. No. 6,799,784 (Rios) issued Oct. 5, 2004 is disclosed an arrangement of this type which is particularly concerned with the mounting of the transverse rails to the underside of the panels.
None of the above devices has achieved commercial success and it is believed that this is primarily due to failure of the products to apply sufficient attention to the construction and details of the mounting arrangement and the formation of the panels by which the panels can be properly mounted and provide a proper stable structural arrangement which can be carried on the truck box and held in position without deformation or twisting.